Stain for brickwork?

2 years ago I had my house extended and specified 'matching brickwork'. The builder supplied some lighter bricks and said they were the best match. Subsequently I found a much better match (almost indistinguishable - thanks very much FNA Special projects - so much for your 40 years 'experience' in the building trade!!) from an extension that was done down the road that was not done by a cowboy. So despite Franks assurances that the bricks would darken with age I am left with an extension that looks like an extension not part of the house. I found that applying waterproof woodstain and preservative to the surface of a few 'test' bricks worked well in darkening the bricks so i wondered if there was on the market any special stain that could be used? its a bit of an arse having to stain each individual brick but worth doing to rectify the poor performance from a less than professional builder. I did find the stain worked extremely well on the cut edges of the bricks where a new window had been installed but I don't want any problems with 'running' when it rains.